Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - Data Sufficiency 3 (Q.No. 2)
Directions to Solve
Each of these questions is followed by three statements. You have to study the question and all the three statements given to decide whether any information provided in the statement(s) is redundant and can be dispensed with while answering the given question.
2.
What is the length of a running train P crossing another running train Q? | |
I. | These two trains take 18 seconds to cross each other. |
II. | These trains are running in opposite directions. |
III. | The length of the train Q is 180 metres. |
Answer: Option
Explanation:
Let the length of the train P be x metres.
II. These trains are running in opposite directions.
III. Length of the train Q is 180 m.
| I. Time taken by P to cross Q = | (180 + x) |  18 = |
(180 + x) |
| Relative speed | Relative speed |
Thus, even with I, II and III, the answer cannot be obtained.
Correct answer is (E).
Discussion:
17 comments Page 1 of 2.
Karan said:
4 years ago
Because we don't have any info of second train's length or speed. So E is correct.
(1)
Sanjay said:
9 years ago
Which is the right answer?
Jayalakshmi said:
1 year ago
Thank you all for explaining.
Jayavarthini said:
1 year ago
Let the length of the train P be x metres.
II. These trains are running in opposite directions.
III. Length of the train Q is 180 m.
I. Time taken by P to cross Q = (180 + x)
18 = (180 + x).
Thus, even with I, II and III, the answer cannot be obtained.
The Correct answer is (E).
II. These trains are running in opposite directions.
III. Length of the train Q is 180 m.
I. Time taken by P to cross Q = (180 + x)
18 = (180 + x).
Thus, even with I, II and III, the answer cannot be obtained.
The Correct answer is (E).
Anand said:
5 years ago
It will be option E because Relative speed (u+v) is not given here.
Ali saeed mohamed said:
5 years ago
Thank you for explaining the answer.
Devraj said:
6 years ago
Thanks all.
D.jyothsna said:
8 years ago
Thank you all for explaining it.
Patel said:
8 years ago
Relative Velocity i.e. (u+v) is required for his question; which is not given here. So, option 'E' is the correct answer.
Sumit said:
1 decade ago
Since these two trains are running in opposite direction their relative speed should be (u+v). Therefore I think option D is the correct answer.
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